Communications networks are often designed to be transparent to end users. The network topology including intermediate nodes in a service provider's network is often hidden.
The Internet Engineering Task Force has created a working-group for application-layer traffic optimization (ALTO). One of the goals of ALTO is to expose network topology to allow applications to make smarter decisions. The IETF working-group has published requests for comments (RFCs) 5693 and 6708 defining various aspects of ALTO.